Synthesis and Characterization of Hindered Polyphosphazenes via Functionalized Intermediates: Exploratory Models for Electro-optical Materials

Several cosubstituent polyphosphazenes were synthesized that incorporate the nonlinear optical chromophore, disperse red 1 (DR-1), linked covalently to the polymer backbone through spacer groups. These polymers have a high chromophore loading (one DR-1 per repeat unit), have glass transition temperatures near 100 °C, and are high refractive index materials (n = ∼1.71). The syntheses were achieved via unconventional reactions that involve functionalized poly(organophosphazenes). Disperse red-1 was linked to the polymers by two different methods that generate either an ester- or an ether-linked system. Techniques such as 1H, 13C, and 31P NMR, gel permeation chromatography, differential scanning calorimetry, UV−vis spectroscopy, and optical birefringence were used to monitor the structures.